There is a type of toilet paper, which is embossed as well as impregnated with water-based lotion chemicals (hereinafter, also referred to as aqueous lotion chemicals).
The toilet paper of this type is embossed so as to have uneven surfaces, which improve the characteristics such as a wiping property and bulkiness property (thickness hand feel and bulkiness), and is impregnated with aqueous lotion chemicals, which improve the characteristics such as a moisture-retaining property (wetness hand feel), flexibility (softness hand feel), and a surface lubricating property (smoothness hand feel).
By the way, it is said that ⅓ of Japanese population suffers from a hemorrhoid disease, and for a person with the disease, it is difficult to rub his or her skin strongly with toilet paper in cleaning operation after excretion. For this reason, such a patient with the hemorrhoid disease is highly interested in toilet paper, which is improved in a wiping property, bulkiness, a moisture-retaining property, softness, and a surface lubrication property, so that he or she desires products satisfying these properties. As for his or her cleaning manner, in many cases, a disease area is cleaned by pressing or press-contacting with the toilet paper so as not to stimulate the disease area.
Meanwhile, there are some consumers, even if who do not suffer from hemorrhoid disease, requesting high-quality toilet papers, and particularly such consumers tend to put a high value on the above-described functions.
In these days, shower toilets become widely used, and after using such a shower toilet, the cleaning operation is performed by press-contacting rather than rubbing with toilet paper. In this case, the toilet paper needs to have high water absorption ability and to effectively conduct the cleaning operation by the above mentioned pressing manner, while it is in a water-absorbing state.
However, conventional toilet paper, which is embossed and is impregnated with aqueous lotion chemicals, has the following disadvantages related to functional advancement and the above wiping manner.
Conventionally, toilet paper, which is embossed and impregnated with chemicals, is produced in a manner such that one entire surface of single base paper or that of multi-ply continuous crepe paper is applied with the chemicals and is embossed by an embossing roll.
Here, by using aqueous lotion chemicals, which are likely to permeate into the paper in the thickness direction, hydrogen bonding between fibers therein is reduced and strength is degraded, since the toilet paper does not generally include a wet paper strength agent in consideration of a water disintegration property or the like.
In order to improve the above mentioned wiping property, the bulkiness, the moisture-retaining property, the softness, and the surface lubricating property, amount of applied aqueous lotion chemicals is increased or depth of each embossed concave portion is enlarged. However, by doing so, paper breakage is caused in the embossing due to the above degraded strength, and hence it is difficult to attain the functional advancement. In the embossing, since a convex portion provided in an embossing roll needs to be pressed against the base paper, a side wall of each embossed concave portion, which is extended from a bottom to a non-embossed portion without pressing by the convex portion, is elongated. Accordingly, as for change in a density state of fibers in the embossed concave portions, at this time, density of the fibers tends to be reduced. Further, in the above mentioned conventional method for manufacturing the toilet paper, since the chemicals are impregnated also into the side wall during the embossing. As a result, tensile strength of the side wall becomes low so that the paper breakage is caused at the side wall during the embossing.
Further, in addition to the above problem in the conventional method for manufacturing the toilet paper, there is a problem also in conventional products. Precisely, since the tensile strength becomes low at the side wall, in case of the above mentioned cleaning manner by pressing with the toilet paper for e.g., the patient with the hemorrhoid disease or the user after the shower toilet, the cleaning operation is performed in a direction along which the side wall is torn, resulting in high frequency of an accident of tearing at the side wall.
Furthermore, a toilet roll applied with oil-based lotion chemicals is also available in the market, but it is used only for a so-called pit toilet in which it is not assumed that used toilet paper is flushed down thereto. This means that there has been no toilet roll, which is applied with the oil-based lotion chemicals and which has a water disintegration property so as to be adapted to a water-saving toilet widely used within our country. Further, there have been no products applied with the oil-based lotion chemicals accepted by consumers, due to stickiness hand feel of the oil-based lotion chemicals.